1. Field of the Invention
The present invention concerns a metallic sleeve usable for forming a contact of a female electric connector. It also concerns a manufacturing method for such a sleeve as well as an electric connector equipped with the sleeve.
The invention finds applications in the general field of electric connectors and in particular power connectors. Power connectors are connectors susceptible to transmit currents of over a hundred ampere, or even several hundreds up to one thousand ampere.
A particular application of the invention is the production of electric connectors for connecting electric vehicles to a power supply battery and to connect the power supply battery to a charge unit for the battery.
The invention notably finds an application in the production of electric connectors for electric forklifts.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Traditionally, electric connectors feature a female contact element, for example a socket and a male contact element, for example a contact pin, susceptible of being inserted into the socket so as to establish a temporary contact for the passage of an electric current. The electric contact is broken when the male element and the female element of the electric connector are separated. A triple technical problem arises traditionally in the production of such electric connectors.
A first technical, primordial problem is the quality of the electric contact between the male and female contact elements when they are assembled. In effect, an insufficient or defective contact is likely to generate an electric resistance to the passage of current and overheating due to the Joule effect. This problem is all the more critical when the electrical currents to transmit are very high.
A second technical problem is that of the hardness or “heftiness” of the connectors. It is a question of the force necessary to exert on the complementary connectors to insert or separate the male and female contact elements. Elevated hardness of the connectors makes their use unwieldy. This difficulty increases also with the intensity of the electric current to be transmitted. In effect, a significant electric current leads to larger dimensions of the contact elements and a larger contact surface. This leads to higher friction and greater difficulty with inserting or separating the contact elements. Accessorily, the search for improved quality of the electric contact can lead to reducing the play between the male and female contact elements and also increase the hardness of the connectors. In other words, the contact quality, and the ease of insertion or separation of the connectors seem to be at cross purposes.
A third technical problem is the durability of the connectors. Durability is understood to be the number of insertion and separation cycles of the complementary connectors during which the contact quality and the transport of current of a predetermined intensity can be guaranteed. Durability is also linked to the hardness of the connectors and the intensity of the currents to be transmitted.
One is familiar with connectors using a female contact element in the form of a socket including contact blades and in particular hyperboloid contact blades. Such connectors are known, for example from the documents CN 104 362 452 or U.S. Pat. No. 5,033,982. The multiple-blade socket aims for increasing the number of contact points between the female part and the male part of the connectors while limiting the mutual friction between these parts.